The present invention relates to apparatuses for transporting plate-shaped work piece which are provided with an air-supplying-type support means that supplies filtered air toward a lower surface of a plate-shaped work piece that is transported so as to contactlessly support the plate-shaped work piece.
Such apparatuses for transporting plate-shaped work piece are used to transport plate-shaped work pieces such as liquid crystal glass substrates. Conventional apparatuses are provided with a drive force application means that applies a drive force in a transporting direction in order to transport a plate-shaped work piece in a horizontal or substantially horizontal orientation. The drive force application means is provided with drive rotors that support both end portions of the plate-shaped work piece in a contacting manner while applying a drive force. The plate-shaped work piece is transported in a horizontal or substantially horizontal orientation, with an intermediate portion thereof supported by the air-supplying-type support means and both end portions of the plate-shaped work piece supported in a contacting manner by the drive rotors. The air-supplying-type support means is provided with numerous air ejection holes provided at a predetermined spacing along the route over which the plate-shaped work piece is transported, and an air supply source including a compression pump, for example, and the supply source and the air ejection portions are connected by a supply duct such that compressed air from the supply source is distributively supplied to the numerous air ejection portions. Moreover, the air-supplying-type support means was designed such that compressed air ejected from the air ejection portions is supplied onto an intermediate portion located between the end portions of the plate-shaped work piece so as to contactlessly support the intermediate portion of the plate-shaped work piece (for example, see JP 2002-321820A).
In an apparatus for transporting a plate-shaped work piece in a vertical or near vertical orientation, the drive force application means applying drive force in the transporting direction is provided with a drive rotor for supporting a lower end portion of the plate-shaped work piece in a contacting manner while applying a drive force, and the lower end portion is supported in a contacting manner by the drive force application means, whereas an intermediate portion of the plate-shaped work piece transported in a vertical or near vertical orientation is supported by the air-supplying-type support means. The air-supplying-type support means is provided with numerous air ejection portions provided at a predetermined spacing along the route over which the plate-shaped work piece is transported, and an air supply source including an air blower, for example, and the supply source and the air ejection portions are connected by supply ducts such that compressed air from the supply source is distributed and supplied to the numerous air ejection portions, and the air-supplying-type support means is configured such that compressed air that is ejected from the air ejection portions is supplied to the intermediate portion of the plate-shaped work piece so as to contactlessly support the intermediate portion of the plate-shaped work piece(for example, see JP 2002-308423A).
With conventional plate-shaped work piece transporting apparatuses, the air-supplying-type support means is designed so that the air supply source and the numerous air ejection portions lined up in the transporting direction are connected by a supply duct, and this necessitated the complex task of connecting the supply source and the numerous air ejection portions so that compressed air does not leak out, making fabrication of the plate-shaped work piece transporting apparatus complicated.
When the route over which the plate-shaped work piece is transported is long, the number of air ejection portions that are provided at a predetermined spacing in the transporting direction increases, and thus, supply sources also are provided at a predetermined spacing in the transporting direction and compressed air is independently supplied to the numerous air ejection portions by the plurality of supply sources. Providing a plurality of supply sources in this manner makes the structure accordingly complicated, and leads to the disadvantage that space for disposing the plurality of supply sources becomes necessary, for example.
Also, with conventional technologies, the amount of air that the air-supplying-type support means supplies toward the lower surface portion of the transported object is constant, and thus the air-supplying-type support means is used only for contactlessly supporting the transported object. Consequently, conventional transporting apparatuses do not allow the transported object to be contactlessly supported and transported at the same time, and thus cannot be adopted to handle different circumstances.
Moreover, with conventional technologies, the air-supplying-type support means is located below the plate-shaped work piece that is transported, and thus the route that passes between the plate-shaped work piece and the air-supplying-type support means and discharges to the side of the air-supplying-type support means is the only discharge route for the filtered air that is supplied onto the lower surface of the plate-shaped work piece, and since the filtered air is not easily discharged it easily pools below an intermediate portion of the plate-shaped work piece. Due to this pooling of air, the plate-shaped work piece is transported in a deformed state in which its intermediate portion bulges upward, and thus a large burden is placed on the plate-shaped work piece.